Structural Design And Mechanical Properties Optimization Of AlSi10Mg Lattice Melted By Selective Laser

Selective laser melting(SLM)is a digital manufacturing technology that can achieve near net forming of parts,and can shape complex lattice structures that cannot be produced by traditional process technologies.This is one of the leading directions for the development of the advanced manufacturing industry in the future.With the rapid development of aviation and aerospace technology,the requirements for lightweight of aircraft and its components are becoming higher and higher.Some special structures are used to replace the traditional solid structures,and lightweight materials are used to lightweight design parts.Therefore,studying the process and structural parameters of lattice structures is of great significance for providing experimental basis for high-quality and rapid manufacturing.Taking the SLM formed aluminum magnesium alloy BCC lattice structure as the research object,the lattice structure was studied through forming experiments and finite element simulation.The main content includes the following aspects:(1)The response surface method was used to study the effects of process parameters such as laser power,scanning speed,and scanning spacing on the difference in density and porosity of the sample,and the process parameters were optimized.The results show that the density first increases and then decreases with the increase of laser power and scanning speed,and then decreases and increases with the increase of scanning distance;The difference in porosity increases with the increase of laser power,scanning speed,and scanning spacing;The optimal process parameter combination obtained through optimization is laser power 335 W,scanning speed 928mm/s,and scanning spacing 0.16mm;The density of the sample prepared with the optimal process parameters is 99.49%,and the difference in porosity is 1.25%,which differs from the predicted values by 0.51% and 0.81%,respectively.(2)The response surface method was used to study the effects of structural parameters such as single cell rod diameter,single cell rod length,and rod inclination angle on the compressive strength and elastic modulus of lattice structures,and multi-objective optimization of structural parameters was carried out.The experimental results show that the compressive strength and elastic modulus increase with the increase of the diameter and inclination angle of the single cell rod,while the compressive strength and elastic modulus gradually decrease as the length of the single cell rod increases;The optimal structural parameters obtained through optimization include a single cell rod diameter of 1.5mm,a single cell rod length of 3mm,and a rod inclination angle of 60°;The BCC lattice structure was prepared according to the optimal structural parameters,with a compressive strength of142.296 MPa and an elastic modulus of 2.702 GPa.Compared with before optimization,the compressive strength increased by 61.77% and the elastic modulus increased by 23.67%;Compared to the predicted values,the proportion of errors is 3.94% and 7.02%,respectively.(3)Lightweight the arm in the frame and mainly study the stress and displacement distribution of the lattice structure arm under lifting force through finite element simulation.The results show that the mass of the lightweight lattice structure arm is reduced by about 23%compared to the solid arm before lightweight;After lightweight,the maximum stress of the lattice structure arm is 79.84 MPa,and the maximum displacement is 0.2237mm;Due to the small maximum displacement of the lattice structure arm,the maximum stress of 79.84 MPa is much lower than the allowable material stress of 251 MPa,which meets the requirements for structural strength and stiffness.